1. Field of the Invention
This invention relates to an image signal recording apparatus for recording an image signal on a recording medium.
2. Description of the Prior Art
The known recording and/or reproducing apparatuses for recording or reproducing a video signal obtained by image sensing means, such as a video camera, on or from a recording medium such as a magnetic disc include an apparatus called an electronic still video camera.
The currently known electronic still video camera is capable of recording or reproducing only a TV signal which is in conformity to the currently prevalent TV system, such as the NTSC system. In the case of the TV signal conforming to the NTSC system, the still video camera is arranged to have 525 scanning lines per frame and about 350 TV horizontal resolution.
However, recent improvement in the picture quality of the video tape recorder has come to stimulate a strong desire for improvement in the picture quality of the electronic still video camera. Since the electronic still video camera is for recording and reproducing still images, the currently attainable resolution is hardly satisfactory. Further, the quality of a picture printed with a video signal reproduced from the magnetic disc is much inferior to that of a picture taken by a camera of the silver-halide type.
Further, a novel TV system of a high picture quality called a high-definition TV system has lately been proposed and is now under experiments. For any electronic still video camera that is capable of matching with this new TV system, the currently prevalent recording and reproduction format is hardly usable as it is for recording and reproduction. Besides, another problem resides in that, even if any new format is developed to enable the still video camera to match with the new TV system, it would be difficult to have interchangeability between the still video cameras adapted for the new and old formats.
For recording, on a recording medium such as a magnetic disc or the like, a still image signal adapted for the above-stated TV system of a high picture quality, it is conceivable to perform multi-channel recording by simultaneously using a plurality of magnetic heads for a plurality of channels. This method, however, encounters a cross-talk problem arising between the magnetic heads if these heads are narrowly spaced for the purpose of increasing the recording capacity of the magnetic medium.